All of the patents, patent applications, technical papers and other references referenced below are incorporated herein by reference in their entirety unless stated otherwise. In additional, extensive disclosure of vehicle occupant sensing is found in U.S. patent application Ser. No. 10/940,881, incorporated by reference herein. Only particularly pertinent background is set forth below.
Optics
Optics can be used in several configurations for monitoring the interior of a passenger compartment or exterior environment of an automobile. In one known method, a laser optical system uses a GaAs infrared laser beam to momentarily illuminate an object, occupant or child seat, in the manner as described and illustrated in FIG. 8 of U.S. Pat. No 5,829,782. The receiver can be a charge-coupled device or CCD or a CMOS imager to receive the reflected light. The laser can either be used in a scanning mode, or, through the use of a lens, a cone of light can be created which covers a large portion of the object. In these configurations, the light can be accurately controlled to only illuminate particular positions of interest within or around the vehicle. In the scanning mode, the receiver need only comprise a single or a few active elements while in the case of the cone of light, an array of active elements is needed. The laser system has one additional significant advantage in that the distance to the illuminated object can be determined as disclosed in U.S. Pat. No. 563,462. When a single receiving element is used, a PIN or avalanche diode is preferred.
In a simpler case, light generated by a non-coherent light emitting diode (LED) device is used to illuminate the desired area. In this case, the area covered is not as accurately controlled and a larger CCD or CMOS array is required. Recently, the cost of CCD and CMOS arrays has dropped substantially with the result that this configuration may now be the most cost-effective system for monitoring the passenger compartment as long as the distance from the transmitter to the objects is not needed. If this distance is required, then the laser system, a stereographic system, a focusing system, a combined ultrasonic and optic system, or a multiple CCD or CMOS array system as described herein is required. Alternately, a modulation system such as used with the laser distance system can be used with a CCD or CMOS camera and distance determined on a pixel by pixel basis.
The optical systems described herein are also applicable for many other sensing applications both inside and outside of the vehicle compartment such as for sensing crashes before they occur as described in U.S. Pat. No. 5,829,782, for a smart headlight adjustment system and for a blind spot monitor (also disclosed in U.S. patent application Ser. No. 09/851,362).
Ultrasonics and Optics
The laser systems described above are expensive due to the requirement that they be modulated at a high frequency if the distance from the airbag to the occupant, for example, is to be measured. Alternately, modulation of another light source, such as an LED, can be done and the distance measurement accomplished using a CCD or CMOS array on a pixel by pixel basis, as discussed below.
Both laser and non-laser optical systems in general are good at determining the location of objects within the two-dimensional plane of the image and a pulsed laser radar system in the scanning mode can determine the distance of each part of the image from the receiver by measuring the time of flight such as through range gating techniques. Distance can also be determined by using modulated electromagnetic radiation and measuring the phase difference between the transmitted and received waves. It is also possible to determine distance with a non-laser system by focusing, or stereographically if two spaced-apart receivers are used and, in some cases, the mere location in the field of view can be used to estimate the position relative to the airbag, for example. Finally, a recently developed pulsed quantum well diode laser also provides inexpensive distance measurements as discussed in U.S. Pat. No. 6,324,453.
Acoustic systems are additionally quite effective at distance measurements since the relatively low speed of sound permits simple electronic circuits to be designed and minimal microprocessor capability is required. If a coordinate system is used where the z-axis is from the transducer to the occupant, acoustics are good at measuring z dimensions while simple optical systems using a single CCD or CMOS arrays are good at measuring x and y dimensions. The combination of acoustics and optics, therefore, permits all three measurements to be made from one location with low cost components as discussed in commonly assigned U.S. Pat. No. 5,845,000 and U.S. Pat. No. 5,835,613,
One example of a system using these ideas is an optical system which floods the passenger seat with infrared light coupled with a lens and a receiver array, e.g., CCD or CMOS array, which receives and displays the reflected light and an analog to digital converter (ADC) which digitizes the output of the CCD or CMOS and feeds it to an Artificial Neural Network (ANN) or other pattern recognition system for analysis. This system uses an ultrasonic transmitter and receiver for measuring the distances to the objects located in the passenger seat. The receiving transducer feeds its data into an ADC and from there, the converted data is directed into the ANN. The same ANN can be used for both systems thereby providing full three-dimensional data for the ANN to analyze. This system, using low cost components, will permit accurate identification and distance measurements not possible by either system acting alone. If a phased array system is added to the acoustic part of the system, the optical part can determine the location of the driver's ears, for example, and the phased array can direct a narrow beam to the location and determine the distance to the occupant's ears.
Adaptation
The adaptation of an occupant sensor system to a vehicle is the subject of a great deal of research and its own extensive body of knowledge as will be disclosed below. There is not believed to be any significant prior art in the field with the possible exception of the descriptions of sensor fusion methods in the Corrado et al. patents discussed above.
Mounting Locations for and Quantity of Transducers
There is little in the literature discussed herein concerning the mounting of cameras or other imagers or transducers in the vehicle other than in the current assignee's patents referenced above. Where camera mounting is mentioned, the general locations chosen are the instrument panel, roof or headliner, A-Pillar or rear view mirror assembly. Virtually no discussion is provided as to the methodology for choosing a particular location except in the current assignee's patents.
Single Camera, Dual Camera with Single Light Source
Farmer et al. (U.S. Pat. No. 6,005,958) describes a method and system for detecting the type and position of a vehicle occupant utilizing a single camera unit. The single camera unit is positioned at the driver or passenger side A-pillar in order to generate data of the front seating area of the vehicle. The type and position of the occupant is used to optimize the efficiency and safety in controlling deployment of an occupant protection device such as an air bag.
A single camera is, naturally, the least expensive solution but suffers from the problem that there is no easy method of obtaining three-dimensional information about people or objects in the passenger compartment. A second camera can be added, but to locate the same objects or features in the two images by conventional methods is computationally intensive unless the two cameras are close together. If they are close together, however, then the accuracy of the three dimensional information is compromised. Also, if they are not close together, then the tendency is to add separate illumination for each camera. An alternate solution is to use two cameras located at different positions in the passenger compartment and a single lighting source. This source can be located adjacent to one camera to minimize the installation sites. Since the LED illumination is now more expensive than the imager, the cost of the second camera does not add significantly to the system cost. The correlation of features can then be done using pattern recognition systems such as neural networks.
Two cameras also provide a significant protection from blockage and one or more additional cameras, with additional illumination, can be added to provide almost complete blockage protection.
Location of the Transducers
The only prior art for occupant sensor location for airbag control is White et al. and Mattes et al. discussed above. Both place their sensors below or on the instrument panel. The first disclosure of the use of cameras for occupant sensing is believed to appear in the current assignee's above-referenced patents. The first disclosure of the location of a camera anywhere and especially above the instrument panel such as on the A-pillar, roof or rear view mirror assembly also is believed to appear in the current assignee's above-referenced patents.
Corrado U.S. Pat. No. 6,318,697 discloses the placement of a camera onto a special type of rear view mirror. DeLine U.S. Pat. No. 6,124,886 also discloses the placement of a video camera on a rear view mirror for sending pictures using visible light over a cell phone. The general concept of placement of such a transducer on a mirror, among other places, is believed to have been first disclosed in commonly assigned U.S. RE 37,736 which also first discloses the use of an IR camera and IR illumination that is either co-located or located separately from the camera.
3D Cameras
Stereo
European Patent Application No. EP0885782A1 describes a purportedly novel motor vehicle control system including a pair of cameras which operatively produce first and second images of a passenger area. A distance processor determines the distances that a plurality of features in the first and second images are from the cameras based on the amount that each feature is shifted between the first and second images. An analyzer processes the determined distances and determines the size of an object on the seat. Additional analysis of the distance also may determine movement of the object and the rate of movement. The distance information also can be used to recognize predefined patterns in the images and thus identify objects. An air bag controller utilizes the determined object characteristics in controlling deployment of the air bag.
Simoncelli in U.S. Pat. No. 5,703,677 discloses an apparatus and method using a single lens and single camera with a pair of masks to obtain three-dimensional information about a scene.
A paper entitled “Sensing Automobile Occupant Position with Optical Triangulation” by W. Chappelle, Sensors, December 1995, describes the use of optical triangulation techniques for determining the presence and position of people or rear-facing infant seats in the passenger compartment of a vehicle in order to guarantee the safe deployment of an air bag. The paper describes a system called the “Takata Safety Shield” which purportedly makes high-speed distance measurements from the point of air bag deployment using a modulated infrared beam projected from an LED source. Two detectors are provided, each consisting of an imaging lens and a position-sensing detector.
A paper entitled “An Interior Compartment Protection System based on Motion Detection Using CMOS Imagers” by S. B. Park et al., 1998 IEEE International Conference on Intelligent Vehicles, describes a purportedly novel image processing system based on a CMOS image sensor installed at the car roof for interior compartment monitoring including theft prevention and object recognition. One disclosed camera system is based on a CMOS image sensor and a near infrared NIR) light emitting diode (LED) array.
Krumm (U.S. Pat. No. 5,983,147) describes a system for determining the occupancy of a passenger compartment including a pair of cameras mounted so as to obtain binocular stereo images of the same location in the passenger compartment. A representation of the output from the cameras is compared to stored representations of known occupants and occupancy situations to determine which stored representation the output from the cameras most closely approximates. The stored representations include that of the presence or absence of a person or an infant seat in the front passenger seat.
The use of stereo systems for occupant sensing was first described by the current assignee in RE 37,736, U.S. Pat. No. 5,845,000, U.S. Pat. No. 5,835,613, U.S. Pat. No. 6,186,537, and U.S. Pat. No. 5,848,802 among others.
Distance by Focusing
A mechanical focusing system, such as used on some camera systems, can determine the initial position of an occupant but is currently too slow to monitor his/her position during a crash or even during pre-crash braking. Although the example of an occupant is used here as an example, the same or similar principles apply to objects exterior to the vehicle. This is a result of the mechanical motions required to operate the lens focusing system, however, methods do exist that do not require mechanical motions. By itself, it cannot determine the presence of a rear facing child seat or of an occupant but when used with a charge-coupled or CMOS device plus some infrared illumination for vision at night, and an appropriate pattern recognition system, this becomes possible. Similarly, the use of three-dimensional cameras based on modulated waves or range-gated pulsed light methods combined with pattern recognition systems are now possible based on the teachings of the inventions disclosed herein and the commonly assigned patents and patent applications referenced above.
U.S. Pat. No. 6,198,998 to Farmer discloses a single IR camera mounted on the A-Pillar where a side view of the contents of the passenger compartment can be obtained. A sort of three-dimensional view is obtained by using a narrow depth of focus lens and a de-blurring filter. IR is used to illuminate the volume and the use of a pattern on the LED to create a sort of structured light is also disclosed. Pattern recognition by correlation is also discussed.
U.S. Pat. No. 6,229,134 to Nayar et al. is an excellent example of the determination of the three-dimensional shape of an object using active blurring and focusing methods. The use of structured light is also disclosed in this patent. The method uses illumination of the scene with a pattern and two images of the scene are sensed with different imaging parameters.
A distance measuring system based on focusing is described in U.S. Pat. No. 5,193,124 and U.S. Pat. No. 5,231,443 (Subbarao) that either be used with a mechanical focusing system or with two cameras, the latter of which would be fast enough to allow tracking of an occupant during pre-crash braking and perhaps even during a crash depending on the field of view that is analyzed. Although the Subbarao patents provide a good discussion of the camera focusing art, it is a more complicated system than is needed for practicing the instant inventions. In fact, a neural network can also be trained to perform the distance determination based on the two images taken with different camera settings or from two adjacent CCD's and lens having different properties as the cameras disclosed in Subbarao making this technique practical for the purposes herein. Distance can also be determined by the system disclosed in U.S. Pat. No. 5,003,166 (Girod) by spreading or defocusing a pattern of structured light projected onto the object of interest. Distance can also be measured by using time of flight measurements of the electromagnetic waves or by multiple CCD or CMOS arrays as is a principle teaching of at least one of the inventions disclosed herein.
Dowski, Jr. in U.S. Pat. No. 5,227,890 provides an automatic focusing system for video cameras which can be used to determine distance and thus enable the creation of a three-dimensional image.
A good description of a camera focusing system is found in G. Zorpette, “Focusing in a flash”, Scientific American, August 2000.
In each of these cases, regardless of the distance measurement system used, a trained pattern recognition system, as defined above, can be used to identify and classify, and in some cases to locate, the illuminated object and its constituent parts.
Illumination
Infrared light
In a passive infrared system, as described in Corrado referenced above, for example, a detector receives infrared radiation from an object in its field of view, in this case the vehicle occupant, and determines the presence and temperature of the occupant based on the infrared radiation. The occupant sensor system can then respond to the temperature of the occupant, which can either be a child in a rear facing child seat or a normally seated occupant, to control some other system. This technology could provide input data to a pattern recognition system but it has limitations related to temperature.
The sensing of the child could pose a problem if the child is covered with blankets, depending on the IR frequency used. It also might not be possible to differentiate between a rear facing child seat and a forward facing child seat. In all cases, the technology can fail to detect the occupant if the ambient temperature reaches body temperature as it does in hot climates. Nevertheless, for use in the control of the vehicle climate, for example, a passive infrared system that permits an accurate measurement of each occupant's temperature is useful. Prior art systems are mostly limited to single pixel devices. Use of an IR imager removes many of the problems listed above and is believed to be novel to the inventions disclosed herein.
In a laser optical system, an infrared laser beam is used to momentarily illuminate an object, occupant or child seat in the manner as described, and illustrated in FIG. 8, of Breed et al. (U.S. Pat. No. 5,653,462). In some cases, a CCD or a CMOS device is used to receive the reflected light. In other cases, when a scanning laser is used, a pin or avalanche diode or other photo detector can be used. The laser can either be used in a scanning mode, or, through the use of a lens, a cone of light, swept line of light, or a pattern or structured light can be created which covers a large portion of the object. Additionally, one or more LEDs can be used as a light source. Also, triangulation can be used in conjunction with an offset scanning laser to determine the range of the illuminated spot from the light detector. Various focusing systems also can have applicability in some implementations to measure the distance to an occupant. In most cases, a pattern recognition system, as defined herein, is used to identify, ascertain the identity of and classify, and can be used to locate, and determine the position of, the illuminated object and/or its constituent parts.
Optical systems generally provide the most information about the object and at a rapid data rate. Their main drawback is cost which is usually above that of ultrasonic or passive infrared systems. As the cost of lasers and imagers has now come down, this system is now competitive. Depending on the implementation of the system, there may be some concern for the safety of the occupant if a laser light can enter the occupant's eyes. This is minimized if the laser operates in the infrared spectrum particularly at the “eye-safe” frequencies.
Another important feature is that the brightness of the point of light from the laser, if it is in the infrared part of the spectrum and if a filter is used on the receiving detector, can overpower the reflected sun's rays with the result that the same classification algorithms can be made to work both at night and under bright sunlight in a convertible. An alternative approach is to use different algorithms for different lighting conditions.
Although active and passive infrared light has been disclosed in the prior art, the use of a scanning laser, modulated light, filters, trainable pattern recognition etc. is believed to have been first disclosed by the current assignee in the above-referenced patents.
Structured Light
U.S. Pat. No. 5,003,166 provides an excellent treatise on the use of structured light for range mapping of objects in general. It does not apply this technique for automotive applications and in particular for occupant sensing or monitoring inside or outside of a vehicle. The use of structured light in the automotive environment and particularly for sensing occupants is believed to have been first disclosed by the current assignee in the above-referenced patents.
U.S. Pat. No. 6,049,757 to Nakajima et al. describes structured light in the form of bright spots that illuminate the face of the driver to determine the inclination of the face and to issue a warning if the inclination is indicative of a dangerous situation. In the current assignee's patents, structured light is disclosed to obtain a determination of the location of an occupant and/or his or her parts. This includes the position of any part of the occupant including the occupant's face and thus the invention of this patent is believed to be anticipated by the current assignee's patents referenced above.
U.S. Pat. No. 6,298,311 to Griffin et al. repeats much of the teachings of the early patents of the current assignee. A plurality of IR beams are modulated and directed in the vicinity of the passenger seat and used through a photosensitive receiver to detect the presence and location of an object in the passenger seat, although the particular pattern recognition system is not disclosed. The pattern of IR beams used in this patent is a form of structured light.
Structured light is also discussed in numerous technical papers for other purposes than vehicle interior or exterior monitoring including: (1) “3D Shape Recovery and Registration Based on the Projection of Non-Coherent Structured Light” by Roberto Rodella and Giovanna Sansoni, INFM and Dept. of Electronics for the Automation, University of Brescia, Via Branze 38, 1-25123 Brescia-Italy; (2) “A Low-Cost Range Finder using a Visually Located, Structured Light Source”, R. B. Fisher, A. P. Ashbrook, C. Robertson, N. Werghi, Division of Informatics, Edinburgh University, 5 Forrest Hill, Edinburgh EH1 2QL; (3) F. Lerasle, J. Lequellec, M Devy, “Relaxation vs. Maximal Cliques Search for Projected Beams Labeling in a Structured Light Sensor”, Proceedings of the International Conference on Pattern Recognition, 2000 IEEE; and (4) D. Caspi, N. Kiryati, and J. Shamir, “Range Imaging With Adaptive Color Structured Light”, IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 20, No. 5, May 1998.
Recently, a paper has been published that describes a structured light camera system disclosed years ago by the current assignee: V. Ramesh, M. Greiffenhagen, S. Boverie, A. Giratt, “Real-Time Surveillance and Monitoring for Automotive Applications”, SAE 2000-01-0347.
Definitions
Preferred embodiments of the invention are described below and unless specifically noted, it is the applicants' intention that the words and phrases in the specification and claims be given the ordinary and accustomed meaning to those of ordinary skill in the applicable art(s). If the applicants intend any other meaning, they will specifically state they are applying a special meaning to a word or phrase.
Likewise, applicants' use of the word “function” here is not intended to indicate that the applicants seek to invoke the special provisions of 35 U.S.C. §112, sixth paragraph, to define their invention. To the contrary, if applicants wish to invoke the provisions of 35 U.S.C. § 112, sixth paragraph, to define their invention, they will specifically set forth in the claims the phrases “means for” or “step for” and a function, without also reciting in that phrase any structure, material or act in support of the function. Moreover, even if applicants invoke the provisions of 35 U.S.C. §112, sixth paragraph, to define their invention, it is the applicants' intention that their inventions not be limited to the specific structure, material or acts that are described in the preferred embodiments herein. Rather, if applicants claim their inventions by specifically invoking the provisions of 35 U.S.C. § 112, sixth paragraph, it is nonetheless their intention to cover and include any and all structure, materials or acts that perform the claimed function, along with any and all known or later developed equivalent structures, materials or acts for performing the claimed function.
“Pattern recognition” as used herein will generally mean any system which processes a signal that is generated by an object (e.g., representative of a pattern of returned or received impulses, waves or other physical property specific to and/or characteristic of and/or representative of that object) or is modified by interacting with an object, in order to determine to which one of a set of classes that the object belongs. Such a system might determine only that the object is or is not a member of one specified class, or it might attempt to assign the object to one of a larger set of specified classes, or find that it is not a member of any of the classes in the set. The signals processed are generally a series of electrical signals coming from transducers that are sensitive to acoustic (ultrasonic) or electromagnetic radiation (e.g., visible light, infrared radiation, capacitance or electric and/or magnetic fields), although other sources of information are frequently included. Pattern recognition systems generally involve the creation of a set of rules that permit the pattern to be recognized. These rules can be created by fuzzy logic systems, statistical correlations, or through sensor fusion methodologies as well as by trained pattern recognition systems such as neural networks, combination neural networks, cellular neural networks or support vector machines.
A trainable or a trained pattern recognition system as used herein generally means a pattern recognition system that is taught to recognize various patterns constituted within the signals by subjecting the system to a variety of examples. The most successful such system is the neural network used either singly or as a combination of neural networks. Thus, to generate the pattern recognition algorithm, test data is first obtained which constitutes a plurality of sets of returned waves, or wave patterns, or other information radiated or obtained from an object (or from the space in which the object will be situated in the passenger compartment, i.e., the space above the seat) and an indication of the identify of that object. A number of different objects are tested to obtain the unique patterns from each object. As such, the algorithm is generated, and stored in a computer processor, and which can later be applied to provide the identity of an object based on the wave pattern being received during use by a receiver connected to the processor and other information. For the purposes here, the identity of an object sometimes applies to not only the object itself but also to its location and/or orientation in the passenger compartment. For example, a rear facing child seat is a different object than a forward facing child seat and an out-of-position adult can be a different object than a normally seated adult. Not all pattern recognition systems are trained systems and not all trained systems are neural networks. Other pattern recognition systems are based on fuzzy logic, sensor fusion, Kalman filters, correlation as well as linear and non-linear regression. Still other pattern recognition systems are hybrids of more than one system such as neural-fuzzy systems.
The use of pattern recognition, or more particularly how it is used, is important to many embodiments of the instant invention. In the above-cited prior art, except that assigned to the current assignee, pattern recognition which is based on training, as exemplified through the use of neural networks, is not mentioned for use in monitoring the interior passenger compartment or exterior environments of the vehicle in all of the aspects of the invention disclosed herein. Thus, the methods used to adapt such systems to a vehicle are also not mentioned.
A pattern recognition algorithm will thus generally mean an algorithm applying or obtained using any type of pattern recognition system, e.g., a neural network, sensor fusion, fuzzy logic, etc.
To “identify” as used herein will generally mean to determine that the object belongs to a particular set or class. The class may be one containing, for example, all rear facing child seats, one containing all human occupants, or all human occupants not sitting in a rear facing child seat, or all humans in a certain height or weight range depending on the purpose of the system. In the case where a particular person is to be recognized, the set or class will contain only a single element, i.e., the person to be recognized.
To “ascertain the identity of” as used herein with reference to an object will generally mean to determine the type or nature of the object (obtain information as to what the object is), i.e., that the object is an adult, an occupied rear facing child seat, an occupied front facing child seat, an unoccupied rear facing child seat, an unoccupied front facing child seat, a child, a dog, a bag of groceries, a car, a truck, a tree, a pedestrian, a deer etc.
An “object” in a vehicle or an “occupying item” of a seat may be a living occupant such as a human or a dog, another living organism such as a plant, or an inanimate object such as a box or bag of groceries or an empty child seat.
A “rear seat” of a vehicle as used herein will generally mean any seat behind the front seat on which a driver sits. Thus, in minivans or other large vehicles where there are more than two rows of seats, each row of seats behind the driver is considered a rear seat and thus there may be more than one “rear seat” in such vehicles. The space behind the front seat includes any number of such rear seats as well as any trunk spaces or other rear areas such as are present in station wagons.
An “optical image” will generally mean any type of image obtained using electromagnetic radiation including X-ray, ultraviolet, visual, infrared, terahertz and radar radiation.
In the description herein on anticipatory sensing, the term “approaching” when used in connection with the mention of an object or vehicle approaching another will usually mean the relative motion of the object toward the vehicle having the anticipatory sensor system. Thus, in a side impact with a tree, the tree will be considered as approaching the side of the vehicle and impacting the vehicle. In other words, the coordinate system used in general will be a coordinate system residing in the target vehicle. The “target” vehicle is the vehicle that is being impacted. This convention permits a general description to cover all of the cases such as where (i) a moving vehicle impacts into the side of a stationary vehicle, (ii) where both vehicles are moving when they impact, or (iii) where a vehicle is moving sideways into a stationary vehicle, tree or wall.
“Vehicle” as used herein includes any container that is movable either under its own power or using power from another vehicle. It includes, but is not limited to, automobiles, trucks, railroad cars, ships, airplanes, trailers, shipping containers, barges, etc. The term “container” will frequently be used interchangeably with vehicle however a container will generally mean that part of a vehicle that separate from and in some cases may exist separately and away from the source of motive power. Thus, a shipping container may exist in a shipping yard and a trailer may be parked in a parking lot without the tractor. The passenger compartment or a trunk of an automobile, on the other hand, are compartments of a container that generally only exists attaches to the vehicle chassis that also has an associated engine for moving the vehicle. Note, a container can have one or a plurality of compartments.
“Out-of-position” as used for an occupant will generally mean that the occupant, either the driver or a passenger, is sufficiently close to an occupant protection apparatus (airbag) prior to deployment that he or she is likely to be more seriously injured by the deployment event itself than by the accident. It may also mean that the occupant is not positioned appropriately in order to attain the beneficial, restraining effects of the deployment of the airbag. As for the occupant being too close to the airbag, this typically occurs when the occupant's head or chest is closer than some distance, such as about 5 inches, from the deployment door of the airbag module. The actual distance where airbag deployment should be suppressed depends on the design of the airbag module and is typically farther for the passenger airbag than for the driver airbag.
“Dynamic out-of-position” refers to the situation where a vehicle occupant, either driver or passenger, is in position at a point in time prior to an accident but becomes out-of-position, (that is, too close to the airbag module so that he or she could be injured or killed by the deployment of the airbag) prior to the deployment of the airbag due to pre-crash braking or other action which causes the vehicle to decelerate prior to a crash.
“Transducer” or “transceiver” as used herein will generally mean the combination of a transmitter and a receiver. In come cases, the same device will serve both as the transmitter and receiver while in others two separate devices adjacent to each other will be used. In some cases, a transmitter is not used and in such cases transducer will mean only a receiver. Transducers include, for example, capacitive, inductive, ultrasonic, electromagnetic (antenna, CCD, CMOS arrays), electric field, weight measuring or sensing devices. In some cases, a transducer will be a single pixel either acting alone, in a linear or an array of some other appropriate shape. In some cases, a transducer may comprise two parts such as the plates of a capacitor or the antennas of an electric field sensor. Sometimes, one antenna or plate will communicate with several other antennas or plates and thus for the purposes herein, a transducer will be broadly defined to refer, in most cases, to any one of the plates of a capacitor or antennas of a field sensor and in some other cases, a pair of such plates or antennas will comprise a transducer as determined by the context in which the term is used.
“Adaptation” as used here will generally represent the method by which a particular occupant or object sensing system is designed and arranged for a particular vehicle model. It includes such things as the process by which the number, kind and location of various transducers are determined. For pattern recognition systems, it includes the process by which the pattern recognition system is designed and then taught or made to recognize the desired patterns. In this connection, it will usually include (1) the method of training when training is used, (2) the makeup of the databases used, testing and validating the particular system, or, in the case of a neural network, the particular network architecture chosen, (3) the process by which environmental influences are incorporated into the system, and (4) any process for determining the pre-processing of the data or the post processing of the results of the pattern recognition system. The above list is illustrative and not exhaustive. Basically, adaptation includes all of the steps that are undertaken to adapt transducers and other sources of information to a particular vehicle to create the system that accurately identifies and/or determines the location of an occupant or other object in a vehicle.
For the purposes herein, a “neural network” is defined to include all such learning systems including cellular neural networks, support vector machines and other kernel-based learning systems and methods, cellular automata and all other pattern recognition methods and systems that learn. A “combination neural network” as used herein will generally apply to any combination of two or more neural networks as most broadly defined that are either connected together or that analyze all or a portion of the input data. “Neural network” can also be defined as a system wherein the data to be processed is separated into discrete values which are then operated on and combined in at least a two-stage process and where the operation performed on the data at each stage is in general different for each of the discrete values and where the operation performed is at least determined through a training process. The operation performed is typically a multiplication by a particular coefficient or weight and by different operation, therefore is meant in this example, that a different weight is used for each discrete value.
A “morphological characteristic” will generally mean any measurable property of a human such as height, weight, leg or arm length, head diameter, skin color or pattern, blood vessel pattern, voice pattern, finger prints, iris patterns, etc.
A “wave sensor” or “wave transducer” is generally any device which senses either ultrasonic or electromagnetic waves. An electromagnetic wave sensor, for example, includes devices that sense any portion of the electromagnetic spectrum from ultraviolet down to a few hertz. The most commonly used kinds of electromagnetic wave sensors include CCD and CMOS arrays for sensing visible and/or infrared waves, millimeter wave and microwave radar, and capacitive or electric and/or magnetic field monitoring sensors that rely on the dielectric constant of the object occupying a space but also rely on the time variation of the field, expressed by waves as defined below, to determine a change in state.
A “CCD” will be generally defined to include all devices, including CMOS arrays, APS arrays, focal plane arrays, QWIP arrays or equivalent, artificial retinas and particularly HDRC arrays, which are capable of converting light frequencies, including infrared, visible and ultraviolet, into electrical signals. The particular CCD array used for many of the applications disclosed herein is implemented on a single chip that is less than two centimeters on a side. Data from the CCD array is digitized and sent serially to an electronic circuit containing a microprocessor for analysis of the digitized data. In order to minimize the amount of data that needs to be stored, initial processing of the image data takes place as it is being received from the CCD array, as discussed in more detail elsewhere herein. In some cases, some image processing can take place on the chip such as described in the Kage et al. artificial retina article referenced above.
The “windshield header” as used herein generally includes the space above the front windshield including the first few inches of the roof.
A “sensor” as used herein can be a single receiver or the combination of two transducers (a transmitter and a receiver) or one transducer which can both transmit and receive.
The “headliner” is the trim which provides the interior surface to the roof of the vehicle and the A-pillar is the roof-supporting member which is on either side of the windshield and on which the front doors are hinged.
An “occupant protection apparatus” is any device, apparatus, system or component which is actuatable or deployable or includes a component which is actuatable or deployable for the purpose of attempting to reduce injury to the occupant in the event of a crash, rollover or other potential injurious event involving a vehicle.
As used herein, a diagnosis of the “state of the vehicle” generally means a diagnosis of the condition of the vehicle with respect to its stability and proper running and operating condition. Thus, the state of the vehicle could be normal when the vehicle is operating properly on a highway or abnormal when, for example, the vehicle is experiencing excessive angular inclination (e.g., two wheels are off the ground and the vehicle is about to rollover), the vehicle is experiencing a crash, the vehicle is skidding, and other similar situations. A diagnosis of the state of the vehicle could also be an indication that one of the parts of the vehicle, e.g., a component, system or subsystem, is operating abnormally.
As used herein, an “occupant restraint device” generally includes any type of device which is deployable in the event of a crash involving the vehicle for the purpose of protecting an occupant from the effects of the crash and/or minimizing the potential injury to the occupant. Occupant restraint devices thus include frontal airbags, side airbags, seatbelt tensioners, knee bolsters, side curtain airbags, externally deployable airbags and the like.
As used herein, a “part” of the vehicle generally includes any component, sensor, system or subsystem of the vehicle such as the steering system, braking system, throttle system, navigation system, airbag system, seatbelt retractor, air bag inflation valve, air bag inflation controller and airbag vent valve, as well as those listed below in the definitions of “component” and “sensor”.
As used herein, a “sensor system” generally includes any of the sensors listed below in the definition of “sensor” as well as any type of component or assembly of components which detect, sense or measure something.
The term “gage” or “gauge” is used herein interchangeably with the terms “sensor” and “sensing device”.